<ul class="stepper" data-mdb-stepper="stepper" data-mdb-stepper-linear="false">

    <form class="needs-validation stepper-form" novalidate>

        <li class="stepper-step stepper-active">

            <div class="stepper-head">

                <span class="stepper-head-icon">1</span>

                <span class="stepper-head-text">step1</span>

            </div>

            <div class="stepper-content py-3">

                <div class="form-outline">

                    <input type="password" id="custom-validation-input-1" class="form-control inputToValidate" required />

                    <label class="form-label" for="custom-validation-input-1">password</label>

                </div>

            </div>

        </li>

        <li class="stepper-step">

            <div class="stepper-head">

                <span class="stepper-head-icon">2</span>

                <span class="stepper-head-text">step2</span>

            </div>

            <div class="stepper-content py-3">

                <div class="form-outline">

                    <input type="text" id="custom-validation-input-2" class="form-control" required />

                    <label class="form-label" for="custom-validation-input-2">step 2</label>

                </div>

            </div>

        </li>

        <li class="stepper-step">

            <div class="stepper-head">

                <span class="stepper-head-icon">3</span>

                <span class="stepper-head-text">step3</span>

            </div>

            <div class="stepper-content py-3">

                <div class="form-outline">

                    <input type="text" id="custom-validation-input-3" class="form-control" required />

                    <label class="form-label" for="custom-validation-input-3">step 3</label>

                </div>

            </div>

        </li>

    </form>

</ul>

<div class="alert fade" id="alertExample" role="alert" data-mdb-color="warning" data-mdb-width="400px" data-mdb-position='top-left' data-mdb-autohide='true' data-mdb-delay='5111'>

    Invalid value

</div>;